Control algorithm and invasive condition detection diagnostic for sensorless drive system disconnect device

Abstract

A sensorless clutch status feedback method including a transmission system disconnect device is provided. To engage the sensorless disconnect device, respective speeds of a motor assembly and the sensorless disconnect device are synchronized to within a certain speed delta threshold of each other, a control system facilitates the engagement of the motor assembly and the sensorless disconnect device, and the control system determines success of the engagement by a motor speed response of the motor assembly (e.g., whether presence of a load is detected).

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 243,161, filed on September 12, 2021, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] Disconnecting devices such as clutches are used to connect and disconnect components of a vehicle's drivetrain. Background Technology

[0004] Disconnecting devices, such as clutches, are used to engage and disengage vehicle drivetrain components. For example, in an electric vehicle with multiple motors, one or more motors and drivetrain components can be disconnected from the wheels using a disconnecting device to reduce energy loss due to non-conservative forces (e.g., friction) between rotating mechanical parts. By disconnecting components during appropriate vehicle conditions, range and efficiency can be increased without affecting vehicle performance. For instance, a disconnecting device can engage a motor to its corresponding wheel to make the rear axle available in high-torque-demand scenarios and / or disengage it in more range / efficiency-focused drive modes to reduce energy loss in the mechanical components.

[0005] In some embodiments, in order to mechanically connect components using a disconnecting device (e.g., a bidirectional controllable mechanical diode (CMD) clutch), a strut on the recessed plate must extend and engage with a recess in the notch on the slotted plate. In some embodiments, the slotted plate is connected to the gearbox output shaft, while the recessed plate is connected to the half-shaft (e.g., the drivetrain) and the wheel. A linear converter controlled by a vehicle dynamics module (e.g., an electronic control unit) can be used to actuate the disconnecting device.

[0006] To lock the clutch plates (e.g., recessed plates and notched plates) without damaging these components, their speeds should be close to each other (e.g., a difference of less than 20 RPM). Specific incremental thresholds for the disconnect device can depend on the type and specifications of the disconnect device. Furthermore, it is desirable to be able to dynamically actuate the disconnect device quickly at any vehicle speed while preventing driver discomfort (e.g., bumps in the vehicle's structure).

[0007] Some disconnectors do not contain any sensors for clutch status feedback. If torque is applied to a disconnector in a partially engaged state, the disconnector may be damaged. For example, if the strut only partially engages with the notch (e.g., it rests on the opening of the notch instead of at the bottom), it can mechanically deform the notch opening. Additionally, a partially engaged disconnector can slip under high torque conditions, which can lead to asymmetrical torque delivery (e.g., using dual motors in a vehicle to independently drive the left and right wheels). Therefore, it is desirable to detect the disconnection state to prevent damage to the disconnector and / or ensure proper torque delivery. Summary of the Invention

[0008] According to some embodiments of this disclosure, the control logic component is used to control the speed of the disconnecting device component prior to engagement to facilitate rapid and successful engagement of the disconnecting device. For example, the control logic component may be used to rapidly synchronize the motor to the corresponding wheel speeds (e.g., differing from each other by a certain number of RPM) before actuating the disconnecting device (e.g., via a linear converter). In some embodiments, the control logic component may determine the synchronization time of the motor and wheel speeds within a statistically significant time window (e.g., implementing speed increments) by comparing the speed difference with a diagnostic threshold. It should be understood that the diagnostic threshold may represent the maximum permissible steady-state error. In some embodiments, applying the diagnostic threshold may include implementing a counter that counts upwards or downwards based on the magnitude of the error in the motor speed.

[0009] In some implementations, a closed-loop speed controller is implemented on the vehicle to control the motor speeds such that the speeds of the inner and outer clutches are matched before the disconnect device is actuated to enter a locked state. In some implementations, the front and / or rear wheels of the vehicle are independently controlled by separate motors, and separate disconnect devices are used to engage and disengage the motors to their respective wheels. For example, two rear motors can engage and disengage simultaneously with their respective wheels. A vehicle dynamics module can be used to determine the engagement and disengagement times of the rear motors and implement a closed-loop speed controller for each motor to control its speed. Due to the high torsional stiffness of the inner components (e.g., rotor, gearbox), the controller gain can be calibrated based on the feedback signal sampling rate and the empirically determined lumped inertia of the inner components to achieve the desired response characteristics. For example, the speed controller can be calibrated to match the speeds of the inner and outer clutches to a difference of 20 RPM within less than 200 ms after the controller receives a command to engage the disconnect device. This enables rapid dynamic actuation of the disconnect device at any vehicle speed.

[0010] According to some embodiments of this disclosure, control logic components are used to determine the state (e.g., locked or unlocked) of a disconnector using available vehicle components or signals. For example, motor speed and wheel speed can be evaluated over a period of time to determine whether the disconnector is locked. Alternatively, a torque pulse can be applied to the motor, and the motor response can be evaluated to determine whether the disconnector is locked.

[0011] In some implementations, the vehicle dynamics module is used to determine the state of one or more disconnect devices. The vehicle dynamics module can access signals for each motor and its corresponding one or more wheels: motor speed, wheel speed, and motor torque feedback (e.g., calculated using motor current). In some implementations, the vehicle dynamics module determines that the disconnect device is locked if one or both of the following conditions are met:

[0012] Condition 1: Motor speed and wheel speed are well correlated over a period of time (e.g., in a statistically significant number of samples).

[0013] Condition 2: The motor speed response to torque indicates the presence of a load on the gearbox output shaft (e.g., full powertrain and vehicle inertia).

[0014] In some implementations, failure of condition 1 alone is sufficient to immediately determine that the disconnector is in the "unlocked" state. If the measured motor speed and wheel speed deviate significantly in response to the input torque (i.e., they are separated), the disconnector must be unlocked.

[0015] In some implementations, condition 1 needs to be met to confirm the “locked” state, but it may not be sufficient to determine that the disconnector is in the “locked” state on its own. Therefore, condition 1 can be supplemented by condition 2. To detect the presence of a load on the gearbox output shaft (condition 2), a reduced-order observer can be implemented to estimate the torque transmitted by connecting the gearbox output shaft to the half-shaft of the wheel. The entire powertrain (including the half-shaft) will be observable if (a) there is consistent positive contact in the gearbox clearance area and (b) the torque bearing assembly of the strut on the recessed plate is fully engaged in the recessed plate. To trigger both conditions as quickly as possible, a speed difference can be introduced between the clutches, which will allow the system to clear the “combination” (disconnector + gearbox) clearance area. Therefore, when engaging the drivetrain (e.g., the rear drivetrain), the vehicle dynamics module will control the motor speed from the wheel speed to a target speed difference (e.g., less than 20 RPM) when attempting to lock the clutch.

[0016] When the clutch is engaged, the reduced-order observer will rely on known transmission parameters to estimate the load torque on the gearbox output shaft. Any high-frequency fluctuations in the load torque above the viscous resistance of the transmission components will indicate the existence of a complete torque transmission path from the wheels to the inner components (rotor + gearbox), thus requiring the clutch to be locked.

[0017] In some implementations, a target speed increment during clutch engagement is set to satisfy two competing priorities:

[0018] Confirmation of Duration: To ensure a consistently fast and seamless transition (e.g., from front-wheel drive to four-wheel drive), the speed difference must be high enough to minimize the time each torque bearing surface takes to traverse the worst-case angular displacement before contacting its mating surface. This worst-case displacement is determined by the angular spacing of the notches.

[0019] Detectable vehicle-level jerk: When the mating surface comes into contact with its mating surface, a higher velocity increment will result in a higher momentum transfer, which will manifest itself as “jerk” or a sudden pulse.

[0020] In some implementations, controller performance can be iteratively optimized to achieve the best possible trade-off between these attributes. The optimization can be performed based on modeling of vehicle components and / or empirical data. In some implementations, the systems and methods disclosed herein determine speed increments by comparing vehicle speed to a threshold, and when the vehicle speed is below the threshold, a first speed increment is selected as the speed increment. In some implementations, the vehicle speed may be above the threshold, in which case the systems and methods select a second speed increment as the speed increment, wherein the second speed increment is greater than the first speed increment.

[0021] The systems and methods described herein engage sensorless disconnectors by controlling motor speed to achieve speed increments, facilitating engagement of the disconnector, monitoring the motor speed response to engagement, and determining whether engagement was successful based on the motor speed response. In some embodiments, the systems and methods may utilize control logic components, control systems, processing circuitry (e.g., control circuitry), memory, power electronics, and any other suitable components to determine the state of the disconnector (e.g., locked or unlocked). In some embodiments, a two-way CMD clutch may include a recessed plate and a notched plate, wherein the recessed plate is coupled to a half-shaft (e.g., a drivetrain) and a wheel, and the notched plate is coupled to a gearbox output shaft. It should be understood that the outer and inner plates can be oriented in any suitable manner. In some embodiments, to facilitate engagement of the disconnector (e.g., a two-way CMD clutch), once the corresponding speeds of the outer and inner plates differ from each other by a certain speed increment threshold (e.g., 15 RPM), a strut from the recessed plate is actuated to extend out and lock into the notch of the notched plate. It should be understood that the speed increment may be based on vehicle speed. In some implementations, to confirm that the disconnector is in a "locked" state, the control system may send a torque command to the motor assembly to monitor the motor speed response. If the corresponding speeds of the motor assembly and the wheels are approximately matched (e.g., a load is detected on the gearbox output shaft), the control system confirms that the disconnector is in a "locked" state. If the corresponding speeds of the motor assembly and the wheels are significantly different (e.g., no load is detected on the gearbox output shaft), the control system determines that the disconnector is in an "unlocked" state.

[0022] In some embodiments, successful engagement may not be determined based on motor speed response. In such cases, the systems and methods disclosed herein apply torque pulses to the motor, determine the pulse motor speed response to the torque pulses, and determine whether engagement is successful based on the pulse motor speed response. In some embodiments, determining successful engagement may include determining the presence of a load connected to the disconnection device.

[0023] In some embodiments, the systems and methods disclosed herein receive wheel speeds and determine a target motor speed based on the wheel speeds and speed increments. In some embodiments, controlling the motor speed to achieve the speed increments may include controlling the motor speed to achieve the determined target motor speed. In some embodiments, the target motor speed may correspond to a speed less than the wheel speed.

[0024] The aforementioned technologies enable independent control of, for example, left and right disconnect devices in a vehicle. Furthermore, they provide techniques for detecting the status of the disconnect devices via, for example, invasive diagnostics, without directly disconnecting the sensors. Attached Figure Description

[0025] The above and other features, properties, and various advantages of this disclosure will become more apparent when considering the following specific embodiments in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 An exemplary vehicle 100 having multiple motors is shown according to some embodiments of the present disclosure;

[0027] Figure 2 An exemplary engageable drive system according to some embodiments of the present disclosure is shown;

[0028] Figure 3 An exemplary control system, motor assembly, disconnection device, and load are shown according to some embodiments of the present disclosure;

[0029] Figure 4A An exemplary recessed plate 402 according to some embodiments of the present disclosure is shown;

[0030] Figure 4B An exemplary notch plate 406 according to some embodiments of the present disclosure is shown;

[0031] Figure 5 An exemplary embodiment of an axle disconnect controller in a vehicle dynamics module according to some embodiments of the present disclosure is shown;

[0032] Figure 6 A flowchart illustrating exemplary steps for managing disconnection device actuation according to some embodiments of the present disclosure is shown;

[0033] Figure 7 A flowchart illustrating exemplary steps for the transient state of an actuating disconnection device according to some embodiments of the present disclosure is shown;

[0034] Figure 8 Example graphs depicting the relationship between the acceleration of an electric motor and the applied torque according to some embodiments of this disclosure are shown;

[0035] Figure 9 Example diagrams depicting a locking scenario according to some embodiments of this disclosure are shown;

[0036] Figure 10 Some embodiments according to this disclosure are shown in Figure 9 The details of the locking scene and state detection technology shown in the image;

[0037] Figure 11 A flowchart illustrating exemplary steps for status confirmation diagnostics of an unlocked state according to some embodiments of the present disclosure is shown;

[0038] Figure 12A flowchart illustrating exemplary steps for status confirmation diagnosis of a locked state according to some embodiments of the present disclosure is shown;

[0039] Figure 13 A flowchart illustrating exemplary steps for status confirmation diagnosis of a locked state according to some embodiments of the present disclosure is shown;

[0040] Figure 14 A flowchart illustrating exemplary steps for engaging and accurately determining the state of a bidirectional controllable mechanical diode clutch according to some embodiments of the present disclosure is shown;

[0041] Figure 15 Example diagrams depicting confirmatory diagnostic performance in low-speed environments according to some embodiments of the present disclosure are shown;

[0042] Figure 16 Example diagrams depicting high-speed engagement events according to some embodiments of this disclosure are shown;

[0043] Figure 17 A flowchart illustrating exemplary steps of disconnecting the controller state machine according to some embodiments of this disclosure is shown; and

[0044] Figure 18 An exemplary notch showing signs of wear is shown according to some embodiments of this disclosure. Detailed Implementation

[0045] In one embodiment, this disclosure relates to a sensorless clutch state feedback method that utilizes control logic components, a control system, processing circuitry (e.g., control circuitry), memory, power electronics, and any other suitable components to determine (e.g., lock or unlock) the state and successfully engage a bidirectional CMD clutch. In some embodiments, the bidirectional CMD clutch includes a recessed plate and a notched plate, wherein the recessed plate is coupled to a half-shaft (e.g., a drivetrain) and a wheel, and the notched plate is coupled to a gearbox output shaft. It should be understood that the recessed plate and the notched plate can be oriented in any suitable manner (e.g., a recessed plate coupled to the gearbox output shaft and a notched plate coupled to the half-shaft and the wheel). To actuate the disconnecting device (e.g., the bidirectional CMD clutch), once the corresponding speeds of the outer and inner plates differ from each other by a certain speed increment threshold (e.g., 15 RPM), a strut from the recessed plate extends out and locks into the notch of the notched plate. In some embodiments, to confirm that the disconnecting device is in a “locked” state, the motor speed response to engagement is monitored. In some embodiments, to confirm that the disconnecting device is in a “locked” state, the control system sends a torque command to the motor assembly to monitor the motor speed response. If the corresponding speeds of the motor assembly and the wheel are approximately matched and the control system also detects a load on the gearbox output shaft (e.g., via a reduced-order observer), the control system confirms that the disconnect device is in a "locked" state. If the corresponding speeds of the motor assembly and the wheel are significantly different, the control system determines that the disconnect device is in a "unlocked" state.

[0046] Figure 1 An exemplary vehicle 100 having multiple motors is shown according to some embodiments of the present disclosure. Figure 1 An exemplary four-wheeled vehicle 100 is depicted, having one motor coupled to each wheel. In some embodiments, the disconnection device of this disclosure can be implemented in a vehicle having any suitable number of motors and wheels. In some embodiments, each wheel may have fewer than or more than one motor (e.g., one motor for the two front wheels and one motor for the two rear wheels), such as Figure 2As shown. The torque level applied by each of one or more components can be determined and generated based on the embodiments described herein. For example, motor assemblies 102, 106 can generate torque clockwise, and motor assemblies 104, 108 can generate torque counterclockwise for vehicle 100 to move forward. More specifically, motor assemblies 102, 104, 106, and 108 may each include an electric motor, a gearbox (e.g., a reduction gear set or pulley set) including a bidirectional controllable mechanical diode (CMD) clutch, a drivetrain connector (e.g., to one of wheels 114, 116, 118, or 120, as shown), auxiliary components (e.g., a linear converter, cooling system, power electronics system, processing circuitry, vehicle dynamics module), any other suitable components, or any combination thereof. Figure 1 As shown, each motor assembly 102, 104, 106, and 108 is coupled to the control system 110 via communication line 124. This communication line may include power leads, control lines, sensor lines, communication buses, any other suitable connection type, and any suitable components or any combination thereof for supplying torque to the respective motor assembly. The control system 110 is shown as coupled to a battery pack 112, although in some examples, the control system 110 may be combined with one or more battery packs or otherwise configured to supply power (e.g., current) to the electric motors of the motor assemblies 102, 104, 106, and 108.

[0047] The control system 110 can be configured to generate torque commands for each of the motor assemblies 102, 104, 106, and 108 via drivetrains 122a and 122b, wherein the commands may indicate one or more vehicle torque levels, and wherein each vehicle torque level may indicate the torque level of each of the motor assemblies 102, 104, 106, and 108. In some embodiments, the control system 110 generates control signals for each of the motor assemblies 102, 104, 106, and 108. The torque generated by the motor assemblies 102, 104, 106, and 108 is delivered to the corresponding wheels 114, 118, 116, and 120 via drivetrains 122a and 122b (e.g., half-shafts). The control signals may include messages, current values, torque values, revolutions per minute (RPM) values, speed increment values, synchronization states, pulse width modulation (PWM) values, any other suitable values, any other information indicating desired operation, or any combination thereof. For example, control system 110 may include a speed controller (e.g., a proportional-integral-derivative (PID) feedback controller), a torque controller, a current controller (e.g., each motor phase of each motor), a position controller, any other suitable controller, or any combination thereof. Furthermore, control system 110 may include adaptive cruise control capabilities, semi-autonomous control capabilities, or fully autonomous control capabilities as described above with respect to vehicle 100 and its components (e.g., motor assemblies 102, 104, 106, and 108, drivetrains 122a, 122b, etc.).

[0048] Figure 2 An exemplary engageable drive system according to some embodiments of the present disclosure is shown. Figure 2 An exemplary drive system 200 is depicted, which includes a motor assembly 202 (e.g., which corresponds to...). Figure 1The vehicle comprises one of the motor assemblies 102, 104, 106, and 108, a gearbox 206, disconnectors 204 and 208, and wheels 210 and 212. Although individually labeled, gearbox 206 and disconnectors 204 and 208 can be combined into a single assembly having any suitable components (e.g., clutch, gear reducer, pulley, bearing, lubrication system, shaft, joint, differential, brake, controller) and any number of disconnectors (e.g., one, two, or more than two). In some embodiments, for example, the vehicle may include front wheels and rear wheels, and the front wheels, rear wheels, or both may be engaged as needed. For example, wheels 210 and 212 may be either front or rear wheels, and if increased torque is desired, a control system (e.g., control system 110) may determine to engage motor assembly 202 and activate disconnectors 204 and 208 via gearbox 206, which may include a bidirectional controllable mechanical diode (CMD) clutch. Disconnectors 204 and 208 may each include a recessed plate and a notched plate, the recessed plate including a strut extending out of and engaging with a notch in the notch of the notched plate. Thus, the disconnector (e.g., a CMD clutch) is in a “locked” state, for example, allowing the vehicle to engage all-wheel drive (AWD) instead of two-wheel drive. In some embodiments, instead of two disconnectors 204 and 208, a single disconnector may be used between the motor assembly 202 and the gearbox 206. In some embodiments, the vehicle may already be moving, so a control system including a speed controller may accelerate the motor assembly 202 before activating disconnectors 204 and 208 to prevent or otherwise reduce interaction torque (e.g., by the speed difference of mating parts). Conversely, in some embodiments, a control system including a speed controller may decelerate the motor assembly 202 before activating disconnectors 204 and 208 to prevent or otherwise reduce interaction torque. In some embodiments, although... Figure 1 Not shown, but each wheel of the vehicle may correspond to a corresponding motor assembly, and each motor assembly may engage / disengage with the corresponding wheel. Therefore, when not used to provide torque, one or more motor assemblies may be disengaged from the gearbox and / or interface.

[0049] Figure 3 An exemplary control system, motor assembly, disconnection device, and load according to some embodiments of the present disclosure are shown. As shown, system 300 includes control system 302 (e.g., which corresponds to...). Figure 1 The control system 110 and the motor assembly 318 (e.g., which corresponds to...) Figure 2 Motor assembly 202 and Figure 1 Motor assemblies 102, 104, 106, and 108 in the motor assembly), disconnection device 320 (e.g., corresponding to...). Figure 2The control system 302 includes disconnection devices 204 and 208, and a load 322. The control system 302 includes a linear converter 304, processing circuitry 306, a memory 308, a communication (COMM) interface 310, power electronics 312, a power supply 314, and one or more sensors 316. In some embodiments, the control system 302 may include any other suitable components or combinations thereof. In some embodiments, the control system 302 may be used to engage and disengage a wheel connected to the load 322 from the motor assembly 318 via the disconnection device 320.

[0050] The control system 302 includes a linear converter 304 that receives commands from processing circuitry 306 (which may include a vehicle dynamics module) and actuates a bidirectional CMD clutch located in disconnection device 320 for engagement or disengagement. The control system 302 includes processing circuitry 306 configured to control the operation of motor assembly 318. Processing circuitry 306 may include a processor, such as, for example, a vehicle dynamics module, a central processing unit having a single or dual core, a bus, logic circuitry, an integrated circuit, a digital signal processor, a graphics processor, an embedded processing device, any other suitable component for reading and executing computer instructions, or any combination thereof. In some embodiments, the vehicle dynamics module may be an electronic control unit. Memory 308 may include any suitable storage device, such as, for example, volatile memory, non-volatile memory, removable storage device, solid-state storage device, optical device, magnetic device, any other suitable component for storing and retrieving information, or any combination thereof. COMM interface 310 may include electrical terminals, a level shifter, a communication module, a connector, a cable, an antenna, any other suitable component for transmitting and receiving information, or any combination thereof. For example, the COMM interface 310 may include an Ethernet interface, a WiFi interface, an optical interface, a sensor interface (e.g., for interacting with one or more sensors 316), any other suitable wired or wireless interface, or any combination thereof. In some embodiments, the COMM interface 310 may include a sensor interface having a power supply, an analog-to-digital converter, a digital-to-digital converter, signal processing equipment, signal conditioning equipment, a connector, electrical terminals, any other suitable components for managing signals to and from the sensor, or any combination thereof. In other embodiments, the sensor interface may be configured to communicate with a current sensor, a position sensor (e.g., a rotary encoder coupled to a motor shaft or gear shaft), a temperature sensor, a voltage sensor, an accelerometer (e.g., a vibration sensor), any other suitable one or more sensors 316, or any combination thereof. In some embodiments, the COMM interface 310 is configured to send control signals indicative of motor commands to the power electronics 312. Power electronic device 312 may include a motor driver, a switch (e.g., an IGBT, a MOSFET), a diode (e.g., a flyback diode), one or more buses (e.g., a DC bus), any other suitable components arranged in any suitable configuration (e.g., an H-bridge, a half-bridge), or any combination thereof. Power supply 314 may include a battery, a battery system (e.g., Figure 1The battery pack 112), leads connected to the battery system, or combinations thereof, are used to supply power to the processing circuit 306, memory 308, COMM interface 310, power electronics 312, one or more sensors 316, motor assembly 318, disconnection device 320, any other suitable components, or any combination thereof.

[0051] In some embodiments, the control system 302 is configured to control engagement at the disconnector 320. For example, the disconnector 320 may include a two-way CMD clutch controlled (e.g., engaged, disengaged) by the control system 302. Furthermore, the disconnector 320 may include one or more actuators (e.g., an electric motor, a solenoid), mechanical actuators (e.g., a grooved plate, a notched plate), hydraulic actuators, pneumatic actuators, sensors (e.g., a speed sensor, a load sensor, a vibration sensor, an optical sensor, a limit switch), any other suitable components for managing the engagement of the motor assembly 318 and the load 322, or any combination thereof.

[0052] In some embodiments, control system 302 may be configured to control motor assembly 318. In some embodiments, motor assembly 318 includes phases corresponding to windings, which are coupled to power electronics 312 via phase leads. In other embodiments, power electronics 312 is configured to receive control signals from processing circuitry 306. Processing circuitry 306 may be configured to implement a motor control algorithm (e.g., an inertial model) based on computer instructions stored in memory 308, which generates control signals based on one or more inputs (e.g., motor speed and wheel speed). For example, processing circuitry 306 may be configured to implement a control scheme for generating current commands based on desired performance (e.g., desired motor position, speed, acceleration, torque, flux, or combinations thereof), and may generate control signals indicating the current commands. In some embodiments, control signals may include pulse width modulation (PWM) signals, pulse density modulation (PDM) signals, analog signals, digital signals (e.g., via a serial or parallel interface), any other suitable signal type, or any combination thereof.

[0053] In some embodiments, control system 302 (e.g., its processing circuitry 306) may be configured to execute a motor control algorithm (e.g., an inertial model) to engage and disengage motor assembly 318 from load 322 via disconnection device 320. In some embodiments, linear converter 304 responds to the motor control algorithm (e.g., an inertial model) from control system 302 and actuates the engagement or disengagement of disconnection device 320. For example, system 300 may be included in an electric vehicle, where load 322 corresponds to a drivetrain or a portion thereof. When more torque is needed to propel the vehicle, motor assembly 318 (e.g., which may initially be disconnected from load 322) may be attached to load 322 (e.g., coupled to the output shaft of a gearbox or the drivetrain) via disconnection device 320. During engagement of motor assembly 318 and load 322, large interactive torques may occur, which may reduce the life of components (e.g., motor assembly 318, the gearbox of load 322, or the clutch of disconnection device 320), damage components, or combinations thereof. In some embodiments, the control system 302 (e.g., or its processing circuitry 306) may be configured to achieve a softer engagement between the motor assembly 318 and the load 322, exhibit a fast acceleration rate, or both. In some embodiments, this disclosure relates to a motor controller (e.g., a speed controller) configured to achieve relatively small or reduced interactive torque during engagement or disengagement of the disconnection device 320.

[0054] Figure 4A An exemplary recessed plate 402 according to some embodiments of the present disclosure is shown, and Figure 4B An exemplary recessed plate 406 according to some embodiments of the present disclosure is shown. The recessed plate 402 includes at least one support 404, and the recessed plate 406 includes at least one recess 408. It should be understood that the recessed plate 402 may include any suitable number of supports 404, and the recessed plate 406 may include any suitable number of recesses 408. In some embodiments, Figure 4A and Figure 4B The components can be implemented in any suitable vehicle type and can be modified to any suitable configuration, including modifications to any of the aforementioned features, such as changes in the position of the struts, changes in the position of the notches, and additional connections to the processing circuitry. The recessed plate 402 and the notch plate 406 can be used for any disconnection device of this disclosure (e.g., disconnection devices 204, 208, and 320).

[0055] This disclosure can be implemented using any type of disconnect device. In some embodiments, this disclosure uses a bidirectional controllable mechanical diode (CMD) clutch. The CMD clutch located in the disconnect device is actuated by a linear converter, which can be directly controlled by a control system in the vehicle, including a vehicle dynamics module. Figure 4A and Figure 4B As shown, in order to mechanically engage the clutch plates, the strut 404 of the recessed plate 402 must extend out and engage in the recess 408 of the recessed plate 406. In some embodiments, when in the "unlocked" state, the speed of the recessed plate 402, corresponding to the speed of the half-shaft and wheel, can differ significantly from the speed of the recessed plate 406 (which corresponds to the speed of the motor and gearbox assembly). It should be understood that in some embodiments, the recessed plate 402 may alternatively be engaged to the motor and gearbox assembly (e.g., the inner component), and the recessed plate 406 may be engaged to the half-shaft and wheel (e.g., the outer component). In order to lock the recessed plate 402 with the recessed plate 406, their respective speeds should be close to each other (e.g., synchronized by a difference of 20 RPM). The specific synchronization threshold of the disconnecting device can depend on the type and specifications of the disconnecting device. For example, a control system including a speed controller can be calibrated to match the respective clutch speeds of the recessed plate 402 and the recessed plate 406 to a difference of 15 RPM within less than 225 milliseconds after the speed controller receives a command from the processing circuitry system for engaging the disconnecting device. It should be understood that the control system can be calibrated so that the corresponding speed of the clutch plate is synchronized within any suitable time period by any suitable synchronization threshold. For dynamic actuation, robust algorithms (e.g., inertial models) can be used to synchronize the motor assembly and wheel speeds in the "unlocked" state. In some embodiments, the disconnector does not contain any sensors for direct clutch status feedback. Therefore, to monitor the clutch status (e.g., locked or unlocked) and ensure the safe delivery of torque through the rear drive system, sensorless diagnostic techniques are used to determine the status of the disconnector based on other available feedback signals (e.g., motor assembly speed in RPM, wheel speed in RPM, or torque pulses in Nm to determine the presence of load).

[0056] Figure 5 An exemplary embodiment of an axle disconnect controller in a vehicle dynamics module according to some embodiments of the present disclosure is shown. As shown, the vehicle dynamics module 500 includes a vehicle torque limiting device 502, a rear axle disconnect device 506, a wheel torque distribution device 510, and a safety management device 512. In some embodiments, the vehicle dynamics module 500 may include any other suitable components or combinations thereof. In some embodiments, the vehicle dynamics module 500 may receive feedback signals (e.g., motor assembly speed in RPM, wheel speed in RPM, and / or torque response pulses in Nm) to determine the presence of a load. In some embodiments, the vehicle dynamics module 500 may be part of processing circuitry and used to determine the state (e.g., locked or unlocked state) of one or more disconnect devices based on the received feedback signals.

[0057] A vehicle (e.g., vehicle 100) may implement an axle disconnect controller (e.g., a rear axle disconnect controller 506) for implementing the functions of this disclosure. In some embodiments, the axle disconnect controller may be implemented by a vehicle dynamics module 500 that also implements other controllers. The vehicle dynamics module 500 includes an axle disconnect controller as a rear axle disconnect controller 506, which includes the function of controlling two linear converters that lock and unlock two rear disconnect devices (e.g., two-way CMD clutches), one of which is for each motor assembly and wheel. As described above, the locking of the disconnect devices occurs when the clutch plate speeds are sufficiently synchronized (e.g., the corresponding speeds of the notch plate and the recessed plate differ from each other by 20 RPM). Therefore, the axle disconnect controller is configured to calculate a target synchronization speed via a speed controller and control the drive unit speed to achieve sufficient synchronization, wherein the drive unit includes the vehicle's corresponding drivetrain, motor assembly, gearbox, and notch plate or recessed plate (e.g., inner component). It should be understood that the drive unit may include any suitable vehicle component or any combination thereof. In some embodiments, the locking process of the two rear disconnect devices uses the vehicle dynamics module 500 to perform closed-loop speed control on the two rear drive units. To enable this function, the wheel torque distribution controller 510 receives torque commands for speed control from an interface having, for example, an axle disconnect controller. The wheel torque distribution controller 510 also receives a limited axle torque signal from the vehicle torque limiting device 502 and delivers the motor torque command to the safety management device 512. In some embodiments, the rear axle disconnect controller 506 can disable any changes to the vehicle dynamics torque command via a downstream controller (e.g., via a drivetrain / clearance controller) to ensure that the speed controller and engagement detection function have complete control over the kinetic energy of the unloaded motor assembly.

[0058] In some implementations, according to this disclosure, sub-functions (e.g., speed estimation, H-bridge control, speed control, engagement state detection) can be used to implement a disconnect controller.

[0059] Figure 6 A flowchart illustrating exemplary steps for managing the actuation of a disconnecting device according to some embodiments of this disclosure is shown. Process 600 may be executed by processing circuitry (e.g., a vehicle dynamics module) located in a control system 110 of vehicle 100. In some embodiments, a linear converter 304 may receive a command from the processing circuitry and activate the disconnecting device between the recessed plate and the notch plate (e.g., a two-way CMD clutch). It should be understood that process 600 and any of its steps can be varied to any suitable configuration, including modifications to any step itself.

[0060] Process 600 begins at step 602, where the control system determines the target device end state. "End state" refers to the final device state (e.g., locked or unlocked state), which corresponds to each of the two possible values ​​of the binary target state flag. For example, as depicted in Table 1 below, the "locked" end state of disconnecting the device may correspond to the binary target state "1" and cause the control system to actuate "forward drive, device disabled" as a subsequent command. Conversely, the "unlocked" end state of disconnecting the device may correspond to the binary target state "0" and cause the control system to actuate "reverse drive, device disabled" as a subsequent command.

[0061]

[0062] If the control system determines that the disconnector is already in the terminated state (step 604), the disconnector remains in the terminated state (step 606), where the speed controller of the control system switches to an inactive state, but the control system may continue to monitor the speed increment threshold between the bidirectional CMD clutches. If the control system determines that the disconnector is no longer in the terminated state (step 604), the control system determines whether the disconnector is in a transient state (step 608). If the control system determines that the disconnector is not in a transient state, the control system determines whether the corresponding speeds of the bidirectional CMD clutches are matched (step 610). If the control system determines that the corresponding speeds of the bidirectional CMD clutches are not matched, the control system actuates the speed controller to match the clutch speeds of the recessed plate and the notch plate to a difference of the speed increment threshold (e.g., a difference of 20 RPM). In some embodiments, a robust algorithm (e.g., an inertial model) may be used to synchronize the motor assembly and wheel speeds in the "unlocked" state. If the control system determines that the corresponding speeds of the bidirectional CMD clutches are matched, the control system determines that the disconnector is in a transient state, which includes speed synchronization of the bidirectional CMD clutches, actuation of the disconnector under speed matching, and confirmation of engagement of the disconnector. A "transient state" refers to an intermediate state (e.g., locked or unlocked) that corresponds to each of the two possible values ​​of the binary target state flag. For example, as described in Table 1 above, a "locked" transient state for disconnecting the device can correspond to a binary target state "1" and cause the control system to actuate "forward drive, device enabled" as a subsequent command. Conversely, an "unlocked" transient state for disconnecting the device can correspond to a binary target state "0" and cause the control system to actuate "reverse drive, device enabled" as a subsequent command.

[0063] If the control system determines that the disconnecting device is in a transient state (step 608), the control system determines whether the H-bridge timeout has expired (step 616). If the H-bridge timeout has not expired, the control system determines that the disconnecting device is in a transient state (step 614). If the H-bridge timeout has expired, the control system closes the H-bridge (step 618), where the H-bridge controls the bidirectional movement of the connected linear actuator. Therefore, the control system performs a status confirmation (step 620), which in some embodiments may be the control system injecting a torque command based on the motor speed response to detect the presence of a load on the gearbox output shaft (e.g., drivetrain). At step 622, the control system determines whether the termination state of the disconnecting device has been confirmed. If the termination state is not confirmed, the control system determines that the disconnecting device is in a transient state (step 614). If the termination state is confirmed, the control system stops speed control and actuates the termination state of the disconnecting device (step 624).

[0064] Figure 7 A flowchart illustrating exemplary steps of the transient state of an actuation disconnection device according to some embodiments of the present disclosure is shown. Process 700 may be executed by processing circuitry (e.g., vehicle dynamics module 500) located in the control system 110 of vehicle 100. In some embodiments, linear converter 304 may receive a command from the processing circuitry and activate the disconnection device between the recessed plate and the notch plate (e.g., a two-way CMD clutch). It should be understood that process 700 and any of its steps can be varied to any suitable configuration, including modifications to any step itself.

[0065] Process 700 begins at step 702, where control system 110 determines that the initial state of the disconnect device is unlocked. Therefore, control system 110 initiates transient state 704 via speed controller actuation of the speed synchronization 706 of recessed plate 402 and notched plate 406. This includes reducing the rear thrust torque limit to zero and matching the speed of the motor assembly to the speed of the wheels with a certain speed increment threshold (e.g., 15 RPM). In some embodiments, a closed-loop motor speed controller on vehicle dynamics module 500 will match the speeds of the outer and inner clutches. The speed increment between these clutches before locking can be within a predetermined RPM amount (e.g., 20 RPM or less at 252 RPM in the motor domain). For example, a reference value for each wheel speed can be calculated by differentiating the output from a high-resolution encoder received via a controller area network (CAN) bus. In some embodiments, different settings of the speed controller can be used based on the vehicle speed or target motor speed to quickly reach the target speed with minimal or no overshoot. Once the control system 110 determines that the corresponding speeds of the bidirectional CMD clutches are synchronized, the control system 110 initiates the actuation 708 of the disconnecting device by enabling the H-bridge controlling the bidirectional movement of the coupled linear actuator to actuate the disconnecting device toward the desired position (e.g., the strut of recessed plate 402 engages with the recess of recessed plate 406). Simultaneously, the disconnecting device continues to match the speeds of the outer and inner clutches. Once the control system 110 determines that the H-bridge timeout has expired, the control system 110 initiates a confirmation 710 of the disconnecting device, which includes disabling the H-bridge, introducing a speed increment (e.g., speed offset) for the speed controller of the control system 110 to incorporate, and integrating torque commands via the speed controller to monitor the speed matching results between the motor assembly and the load on the gearbox output shaft (e.g., the drivetrain). Once the control system 110 determines that the disconnecting device is locked, the control system 110 actuates the end state 712, which includes disabling the speed controller. In some embodiments, the control system 110 may continue to monitor the speed increment between the outer and inner clutches.

[0066] Figure 8 An example graph depicting the relationship between the acceleration of an electric motor and the applied torque according to some embodiments of this disclosure is shown. The slope of the acceleration vs. torque curve is approximately 0.017 kg. m 2 This corresponds to the effective inertia of the motor assembly and any connecting parts (e.g., gearbox, inner disconnector clutch) when the disconnector is in the "unlocked" state. Knowing the effective inertia of the unloaded inner components, a purely proportional motor speed regulator can be developed and tuned, based on... Figure 8 Assume there is no significant static offset or phase delay (e.g., due to viscous resistance).

[0067]

[0068] in:

[0069] K = Controller gain

[0070] J = Effective inertia of the inner component

[0071] T = Torque request (controller output)

[0072] A controller gain of 10 would roughly correspond to a time constant of 100 milliseconds, which would fit well within the stability constraints imposed by a 100 Hz task rate (e.g., a 10 ms sampling interval). In some implementations, the torque command from the speed controller would be limited to, for example, + / - 40 Nm. Figure 8 The data indicates that this corresponds to approximately 2,400 rad / s. 2 Motor speed conversion rate (e.g., 23,000 RPM / s).

[0073] To confirm that the speed increment between the inner and outer clutches has stabilized within an acceptable range, the filtered speed error signal within a statistically significant time window can be examined. In some implementations, the error must be within a calibrable threshold to pass the verification. In some implementations, two thresholds will be used to implement the de-jitter strategy:

[0074] Diagnostic threshold—represents the maximum permissible steady-state error. Instantaneous offsets exceeding this threshold will be de-jittered.

[0075] Best Possible Unacceptable (BPU) Threshold — This represents the maximum instantaneous error. Any instantaneous offset exceeding this threshold will immediately cause the diagnostic to fail.

[0076] For speed matching with the unlocked disconnector, based on observed controller performance, the diagnostic threshold can be 20 RPM in the wheel domain (e.g., 26 rad / s in the motor domain). The BPU threshold can be 40 RPM in the wheel domain (e.g., 52 rad / s in the motor domain). This threshold can be selected within acceptable limits specified for the specific disconnector used. Therefore, a difference between the motor and wheel speeds greater than the BPU threshold will immediately cause this test to fail. Errors between 0 RPM and 40 RPM will be handled using debounce logic. For example, a debounce counter can increment when the error is between 0 RPM and 20 RPM and decrement when the error is between 20 RPM and 40 RPM. If the debounce counter increments beyond the threshold within a predetermined time or sample size, the test will pass. It should be understood that the thresholds used herein are merely illustrative, and any suitable threshold can be used appropriately to determine whether the speed matches. It should also be understood that these tests can be repeated (e.g., for up to a predetermined amount of time, such as 0.5 seconds or 1.0 seconds) until they pass.

[0077] In some implementations, asymmetric de-jitter logic can be used to shorten the duration of the speed synchronization phase actuated by the disconnect device. For example, the de-jitter counter may increment by more than 1 for each sample or the time during which the speed error is below a diagnostic threshold. However, the asymmetric de-jitter logic may be dependent on the stability of the speed controller. For example, if the speed controller exceeds the speed target, the asymmetric de-jitter logic used to shorten the time required to determine whether the speed is matched may incorrectly determine the speed match before the motor speed stabilizes. In some implementations, the speed matching logic may be prone to errors due to transmission dynamics and wheel speed measurement errors during vehicle startup (e.g., from a standstill). This can be exacerbated when the wheels are on low-friction surfaces. Therefore, vehicle stability control and vehicle dynamics information can be used to modify the logic (e.g., modifying the thresholds to make them more lenient) to account for these vehicle conditions and reduce errors.

[0078] In some implementations, the following signals can be used by the vehicle dynamics module and can be used to estimate the state of the disconnect device: motor component speed (e.g., from the controller area network (CAN bus)), wheel speed, speed controller torque command, and motor torque feedback. In some implementations, the disconnect device can be determined to be locked if the following conditions are met:

[0079] Condition 1: Motor speed and wheel speed are well correlated in a statistically significant number of samples.

[0080] Condition 2: The motor speed response to the torque command indicates that there is a load on the gearbox output shaft (full powertrain and vehicle inertia).

[0081] In some implementations, condition 1 is similar to the speed synchronization check described above. In some implementations, meeting condition 1 is necessary but not sufficient to confirm the "locked" state. Therefore, condition 1 can be supplemented by condition 2. Conversely, failure of condition 1 is sufficient to immediately confirm the "unlocked" state. When there is no load on the gearbox output, the motor response to the torque command will follow the inner inertia model derived above. Conversely, if a load is present, the motor speed response will be affected by transmission dynamics and the effective inertia of the vehicle. Therefore, whether the gearbox output shaft is loaded can be inferred by comparing the measured motor speed response with the predicted response of the unloaded motor. In some implementations, the clutch is determined to be locked if any of the following conditions are met:

[0082] Condition 1: The predicted no-load speed response deviates significantly from the measured motor component speed.

[0083] Condition 2: The dynamic characteristics of the transmission system are observed in the inertial model, and the dynamic characteristics of the transmission system deviate from the measured motor speed.

[0084] Condition 2 can be verified by applying a high-pass or band-pass filter to the model deviation of the speed measurement results. The resulting signal will isolate the frequency content generated by the resonance of the transmission system.

[0085] To confirm that the disconnect device is unlocked, each rear motor assembly can be accelerated independently of its corresponding wheel. If the motor and wheel speeds deviate significantly from the torque command (e.g., a torque pulse transmitted by the control system), the outer and inner clutches must disengage (e.g., be in the "unlocked" state).

[0086] When the disconnector is locked, the no-load inertia model will deviate from the measured motor speed when the dynamic characteristics of the transmission system are present in the system (e.g., the half-shaft torque is non-zero). This may occur when the disconnector clutch is fully locked (e.g., the strut is fully engaged with the notch) and there is consistent positive contact in the gearbox (i.e., any mechanical clearance or gap between gearbox components has been cleared). To trigger these two conditions as quickly as possible, a speed difference can be introduced between the clutches, which will allow the system to clear the "combination" (e.g., disconnector and gearbox) clearance zone. For example, a speed difference can be introduced in two ways: closed-loop speed control or open-loop constant torque pulses (e.g., linear ramp speed). With the disconnector locked, either method will result in a rapid (e.g., high-frequency) deviation between the no-load inertia model and the measured motor speed after the inner components (e.g., motor, gearbox, inner clutch) accelerate through the effective clearance zone, such as... Figure 10 As shown (e.g., the constant torque pulse method).

[0087] Figure 9 Example diagrams depicting a locking scenario according to some embodiments of this disclosure are shown. As described above, to confirm that the disconnection device is locked, each rear motor assembly can be accelerated independently of its corresponding wheel by a torque pulse. If the motor and wheel speeds are significantly similar in response to a torque command (e.g., a torque pulse transmitted by the control system), the control system determines that the outer and inner clutches are engaged (e.g., in a “locked” state). Graph 906 shows the disconnection state before, during, and after the locking scenario, as well as the different stages of locking (e.g., speed synchronization 706, actuation 708, and confirmation 710). Graph 904 shows the torque command transmitted by the control system at the beginning of the speed synchronization stage 706 to engage the bidirectional CMD clutches (e.g., recessed plate 402 and notched plate 406). Graph 902 shows two pairs of X, Y coordinates that reflect the points before and after the control system generates a second torque pulse to confirm that the motor assembly speed matches the wheel speed. This second torque pulse appears in graph 904, aligned with the confirmation stage 710 in graph 906.

[0088] Figure 10 Some embodiments according to this disclosure are shown in Figure 9 The improvements to the locking scenario and state detection technology are shown in Figure 1002. Figure 1002 illustrates how the no-load inertial model prediction slowly deviates from the measured results due to inaccuracies in the model parameters. Figure 1008 shows the speed error, where the model deviation is high-pass filtered at an angular frequency of 2 Hz during the actuation and confirmation phases. The high-pass filtering removes the drift, making the diagnostics more effective. Note that to make the calculation robust to any dynamic characteristics introduced by downstream control algorithms (e.g., drivetrain controllers), the measured motor torque (e.g., calculated using motor current) can be used instead of the torque command from the disconnect controller to predict the no-load speed response. Figure 1006 shows the disconnect state before, during, and after the locking scenario, as well as the different stages of locking (e.g., speed synchronization 706, actuation 708, and confirmation 710). Figure 1004 shows the torque generated by the rear drive unit, which is used to accelerate the motor and gearbox assembly to achieve speed synchronization between the CMD clutch plates. Once the "locked" state is confirmed, the torque smoothly increases to accelerate the vehicle in four-wheel drive.

[0089] Figure 11 A flowchart illustrating exemplary steps for status confirmation diagnostics for an unlocked state according to some embodiments of this disclosure is shown. Process 1100 may be performed by the vehicle's control system 302 (corresponding to...). Figure 1The process is executed by the processing circuitry 306 (e.g., a vehicle dynamics module) in the control system 110. In some embodiments, the linear converter 304 may receive a command from the processing circuitry 306 and initiate the disconnection between the recessed plate 402 and the notch plate 406 (e.g., a two-way CMD clutch). It should be understood that process 1100 and any of its steps can be changed to any suitable configuration, including modifications to any step itself.

[0090] Process 1100 begins between steps 1110 and 1112, where actuation is permitted, and the control system proceeds to step 1112 after determining that the disconnect device is in a “locked” state. To unlock the bidirectional CMD clutch, the control system synchronizes the corresponding speeds of the motor assembly and wheels at 1112 (e.g., reducing the rear drive torque to zero), actuates the clutch at 1114 (e.g., disengaging the support of the recessed plate from the recess of the recessed plate), and performs invasive diagnostics in the gearbox at 1102 to introduce (or attempt to introduce) a speed mismatch between the motor assembly and the wheels. Invasive diagnostics may include, for example, torque pulses that will cause a violation of the BPU threshold discussed in paragraph

[0062] above for a short period of time (e.g., 100 ms or less). In some embodiments, based on an inside inertia model, a 10 Nm torque pulse will cause a violation of the 52 motor rad / s BPU threshold within approximately 94 milliseconds. If the motor assembly and wheel speeds are matched (e.g., a load is detected on the gearbox output shaft at 1104), the control system determines that the outer and inner clutches are mechanically locked at 1110, and another attempt to unlock the clutches can be made (e.g., repeating steps 1112, 1114, and 1102). However, if the control system detects a runaway motor speed at 1106 (e.g., a significant difference between the motor speed and wheel speed), the control system determines that the outer and inner clutches are unlocked at 1108.

[0091] Figure 12 A flowchart illustrating exemplary steps for status confirmation diagnostics of a locked state according to some embodiments of the present disclosure is shown. Process 1200 may be performed by the vehicle's control system 302 (corresponding to...). Figure 1 The process is executed by the processing circuitry 306 (e.g., a vehicle dynamics module) in the control system 110. In some embodiments, the linear converter 304 may receive a command from the processing circuitry 306 and initiate the disconnection between the recessed plate 402 and the notch plate 406 (e.g., a two-way CMD clutch). It should be understood that process 1200 and any of its steps can be changed to any suitable configuration, including modifications to any step itself.

[0092] Process 1200 begins at step 1210, where the control system determines that the outer and inner clutches are unlocked. The unlocked state may be entered due to the difference between the wheel speed and the motor assembly speed during locking or after successful unlocking of the disconnect device. When in the unlocked state, locking actuation is permitted. In response to locking actuation, the control system attempts to lock the outer and inner clutches by entering a transient state, which includes synchronizing the corresponding speeds of the motor assembly and wheels at 1212 (e.g., matching the corresponding speeds of the motor assembly and wheels such that their difference is below a speed increment threshold), actuating the outer and inner clutches to engage at 1214 and monitoring inertial model deviations (e.g., torque pulses), and optionally, injecting a torque pulse at 1202 to determine if a load is present on the gearbox output shaft. If the motor assembly and wheel speeds are matched, and an additional load is detected on the gearbox output shaft at 1204, the control system determines that the outer and inner clutches are mechanically locked at 1206. If, in response to the injected torque pulse at 1202, the control system detects speed runaway of the motor assembly at 1208, then the control system determines at 1210 that the outer and inner clutches are unlocked. When the clutch plates are locked, a closed-loop speed controller (such as / similar to the controller described above) can be used to control the motor speed to a target difference from the wheel speed during the speed synchronization phase, such as... Figure 10 As shown. Then, when the clutch is actuated at 1214, at 1204, the inertial model deviation can be calculated to detect when the clutch becomes mechanically engaged, where the inertial model deviation has an optional high-pass filter to isolate the drivetrain dynamics. If successful, this passive load detection method will allow the logic to skip the confirmation phase 1202, resulting in less noticeable jerk and a faster transition to, for example, all-wheel drive (AWD). However, if the inertial model deviation remains small during the actuation phase, the output load detection logic will continue to the confirmation phase at 1202.

[0093] Figure 13 A flowchart illustrating exemplary steps for status confirmation diagnosis of a locked state according to some embodiments of the present disclosure is shown. Figure 12 The flowchart steps are in Figure 13 The flowchart illustrates this, except Figure 13 The confirmation phase includes control system 302 (corresponding to Figure 1The control system 302 (110) controls the speed of the motor assembly (e.g., using a closed-loop PID controller) at 1302 to a target speed increment between the corresponding speeds of the motor assembly and the wheel. If at 1208 the difference between the corresponding speeds of the motor assembly and the wheel is greater than the target speed increment, the control system 302 determines at 1210 that the outer and inner clutches are unlocked and returns to the speed synchronization phase of the transient state at 1212. Conversely, if the difference between the corresponding speeds of the motor assembly and the wheel remains below the target speed increment, the control system 302 monitors for the presence of a load on the output shaft of the gearbox (e.g., using a reduced-order observer). If a load is detected at 1204, the control system 302 determines at 1206 that the outer and inner clutches are locked. It should be understood that any suitable target speed increment can be used.

[0094] Figure 14 A flowchart illustrating exemplary steps for engaging and accurately determining the state of a bidirectional controllable mechanical diode clutch according to some embodiments of the present disclosure is shown. Process 1400 may be controlled by a control system 302 located in the vehicle (corresponding to...) Figure 1 The process is executed by the processing circuitry 306 (e.g., a vehicle dynamics module) in the control system 110. In some embodiments, the linear converter 304 may receive a command from the processing circuitry 306 and initiate the disconnection between the recessed plate 402 and the notch plate 406 (e.g., a two-way CMD clutch). It should be understood that process 1400 and any of its steps can be changed to any suitable configuration, including modifications to any step itself.

[0095] Process 1400 begins at step 1402, where the control system controls the motor speed via a speed controller to achieve a speed increment (e.g., within 20 RPM) relative to the corresponding wheel speeds (i.e., speed synchronization). In some embodiments, this may include the control system reducing the propulsion torque of the rear drivetrain to zero or near zero. The motor assembly may be coupled to a disconnect device via the drivetrain, the disconnect device comprising outer and inner clutches (e.g., recessed plates and notched plates). In some embodiments, the notched plate may correspond to the speed of the gearbox motor assembly, and the recessed plate may correspond to the speed of the half-shaft and the wheel. It should be understood that the orientation of the clutches may be switched such that the notched plate corresponds to the speed of the half-shaft and the wheel, and the recessed plate corresponds to the speed of the gearbox and the motor assembly. Once the corresponding speeds of the motor assembly and the wheel are matched to the difference of the speed increment, the control system engages the disconnect device at 1404. In some embodiments, engagement of the disconnect device at 1404 includes enabling an H-bridge controlling the bidirectional movement of the coupled linear actuator to actuate the disconnect device toward a desired position (e.g., the strut of the recessed plate engages with the notch of the notch in ... In some embodiments, the control system continues to synchronize the speeds of the motor assembly and the wheels while the disconnector engages. At step 1406, the control system detects the motor assembly speed response to motor torque during engagement. In some embodiments, the motor response includes monitoring the speed matching result between the motor assembly and the corresponding wheel during engagement and / or in response to torque pulses. At step 1408, the control system determines the success of engagement based on the motor speed response. If the speed of the motor assembly differs significantly from the speed of the wheel, the control system determines that the engagement of the disconnector 1404 was unsuccessful. Conversely, if the speed of the motor assembly matches the speed of the wheel and a load is detected on the gearbox output, the control system determines that the engagement of the disconnector at 1404 was successful.

[0096] Figure 15 Example diagrams depicting the confirmatory diagnostic performance in low-speed environments according to some embodiments of the present disclosure are shown. For example, Figure 15The graphs depicted show the confirmatory diagnostic performance of the motor / wheel speed difference at 20 rad / s at 5 mph. Graph 1502 illustrates the engagement of the disconnect device in the rear drive system, where at 1514 the motor speed 1510 matches the shifted wheel speed 1512, indicating that the strut of recessed plate 402 is locked to the notch of recessed plate 406. This aligns with the actuation phase 708 of graph 1506. Graph 1504 shows the torque command 1516 transmitted by the control system at the start of speed synchronization phase 706 to engage the bidirectional CMD clutches (e.g., recessed plate 402 and recessed plate 406). Graph 1504 then depicts a second torque command 1518, which is used to maintain the speed difference between these clutch plates after engagement. Graph 1506 shows the disconnected state before, during, and after the locking scenario, as well as the different phases of locking (e.g., speed synchronization 706, actuation 708, and confirmation 710). Graph 1508 shows the measured difference between the corresponding speeds of the motor assembly and the wheel, and the predicted difference corresponding to the torque generated by the motor (e.g., using an unloaded inertia model). The confirmation phase 710 is significantly aligned with the deviation between the predicted and measured differences in graph 1508.

[0097] Figure 16 Example diagrams depicting high-speed engagement events according to some embodiments of this disclosure are shown. The high-performance algorithm includes calibration improvements to rapidly detect and react to "sudden changes" or "bumps" in motor speed when the disengagement device engages. Figure 16 The engagement event described occurs at a speed of 60 miles per hour, and takes approximately 160 milliseconds from the initial engagement request to confirmation of the "locked" state. However, it should be understood that the actual time may depend on the relative angular position of the groove plate's support relative to the notch of the groove plate at the moment the linear translator reaches the fully engaged position. For example, Figure 16The same engagement shown can take up to 600 milliseconds, depending on the initial angular offset. In graph 1602, the motor speed 1612 rapidly increases from 0 radians / second (i.e., stopped) to over 800 radians / second due to the torque command 1614 depicted in graph 1604. As the motor speed 1612 is synchronized to a permissible speed increment with the changed wheel speed 1610, the control system continues to engage the CMD clutch and maintains that speed increment during actuation. The motor speed 1612 proceeds to match the changed wheel speed 1610, while the predicted and measured motor speeds suddenly deviate, as shown in graph 1608, confirming that the inner and outer clutches are in a “locked” state. Graph 1606 shows the disengagement state before, during, and after the locking scenario, as well as the different phases of locking (e.g., speed synchronization 706 and actuation 708). As depicted in graph 1606, the short time spent by the disengagement device in the actuation phase 708 indicates rapid engagement of the clutch plates. Graph 1608 shows the measured and predicted speed increments between the motor assembly and the wheel, including sudden deviations in the high-pass filtered signal (e.g., confirmation of a "locked" state). Graph 1608 also includes the Best Possible Unacceptable (BPU) threshold 1616, which represents the maximum instantaneous error that the control system will allow.

[0098] In some implementations, determining the ideal velocity increment for verification requires a trade-off between two conflicting requirements:

[0099] 1. Confirm duration: e.g. Figure 4A and Figure 4B As shown, the recessed plate may include 15 recesses. Therefore, once the supports of the recessed plate are fully extended, the worst-case relative angular displacement between the clutches before each support engages in the nearest recess will be 2. π / 15 radians. When converted to a motor unit (assuming a gear reduction of 12.6), this corresponds to 5.28 radians, or 84% of the motor's full rotation. To keep the worst-case confirmation time within acceptable limits, such as 300 milliseconds, the speed increment must have a minimum value of 5.28 radians / 0.3 seconds = 17.59 radians / second.

[0100] 2. Noticeable vehicle-level jerk: Higher speed increments will result in greater momentum transfer during the confirmation state, which will manifest as more pronounced vehicle-level jerk. Therefore, at low speeds (e.g., 15 mph and below) and low vehicle acceleration, speed increments of 15 radians per second or higher will result in a very noticeable and audible dull metallic sound and jerk during a disconnector lockout event.

[0101] In some implementations, two calibrated speed increment targets can be stored, one for high power (e.g., high speed and / or torque) and one for low power (e.g., low speed and / or torque), as follows:

[0102] 1. A high-power speed increment of 25 radians / second is used to accelerate engagement during maneuvering, where responsiveness and short engagement duration are prioritized, and the signal-to-noise ratio of engagement jerk is low.

[0103] 2. For other scenarios (e.g., engagement or drive mode change during deceleration), use a low-power speed increment of 10 radians / second to reduce the signal-to-noise ratio of engagement jerk while extending the duration of the confirmation phase.

[0104] Figure 17 A flowchart illustrating exemplary steps of a disconnect controller state machine according to some embodiments of this disclosure is shown. Process 1700 may be executed by processing circuitry 306 (e.g., a vehicle dynamics module) located in a vehicle control system 302. In some embodiments, a linear converter 304 may receive a command from processing circuitry 306 and initiate the disconnect controller. It should be understood that process 1700 and any of its steps may be changed to any suitable configuration, including modifications to any step itself.

[0105] Process 1700 begins at step 1702, where the control system has not yet determined the state of the disconnector (e.g., locked or unlocked), and is therefore marked "undefined". In this case, the control system confirms that the disconnector is in a "locked" state, and the control system proceeds to step 1710. At step 1706, the control system determines that the disengagement criteria for unlocking the disconnector have been met (e.g., a request from the driver or upstream control logic to use an extended-range front-wheel drive mode). At step 1708, the control system unlocks the disconnector using the control logic and intrusive state detection method described in this disclosure. At step 1704, the control system determines that the engagement criteria for locking the disconnector have been met (e.g., an all-wheel drive mode requested by the driver or upstream control logic to provide higher acceleration). At step 1710, the control system locks the disconnector using the control logic and intrusive state detection method described in this disclosure. In some embodiments, although the disconnector is in a "locked" state at 1704, the control system may determine that the "locked" state confirmation was unsuccessful (e.g., a torque command caused the motor speed to run away), which causes the control system to determine that the disconnector has "failed" at 1712. Similarly, although the device is in the "unlocked" state at 1706, the control system may determine that the "unlocked" state confirmation was unsuccessful (e.g., a torque command caused speed matching between the motor assembly and the wheels, or a load was detected on the gearbox output), causing the control system to determine that the disconnect device has "failed" at 1712. In some embodiments, when the device is in the "locked" state at 1704, disengagement can be requested (e.g., due to the driver changing their mind), in which case process 1700 proceeds to the "unlocked" state at 1706. Conversely, although the device is in the "unlocked" state at 1706, engagement can be requested (e.g., due to the driver changing their mind), in which case process 1700 proceeds to the "locked" state at 1704.

[0106] In some implementations, the actuation of the vehicle's disconnection device can be tracked over time. For example, the number of actuations and metrics derived from the actuations (e.g., lockout faults) can be stored or accumulated to track wear and for diagnostic purposes. For instance, a notch may wear easily when torque is applied to a partially engaged strut.

[0107] Figure 18An exemplary notch showing signs of wear is shown according to some embodiments of the present disclosure. Notch 1802 shows signs of wear on the chamfered edge 1804 of notch 1802. Repeated partial engagement can lead to this type of wear, which in turn can deposit debris in notch 1802 and increase the likelihood of further partial engagement in the future by preventing the struts from fully locking into notch 1802. This type of wear can be reduced by appropriately selecting the speed increment (e.g., a negative locking speed increment). The technique and logic of the present disclosure reduce the probability of strut partial engagement that will transmit torque in the intended drive direction and ensure that they always achieve full engagement, which can be achieved by locking the clutch at a speed difference opposite to the intended torque transmission direction. This negative speed difference causes the opposing strut assembly to engage first on the notch plate and transmit the load. Meanwhile, the strut assembly intended to transmit propulsion torque will remain unloaded and be able to fully extend into the notch.

[0108] In some implementations, a vehicle storage device (e.g., 16 bytes of space in memory) is used to track the number of locking and unlocking events during the vehicle's lifespan. In some implementations, each count (e.g., left rear lock, left rear unlock, right rear lock, and right rear unlock) occupies 4 bytes, allowing tracking up to 4.29 billion actuations. In some implementations, an "actuation" is defined as a current pulse from a linear actuator, followed by a confirmation phase (if applicable). Therefore, if multiple actuation attempts occur during transition to a given target state, these will be counted separately. The lock count for each disconnection device can be sent to diagnostic equipment or a remote storage device for fleet assessment.

[0109] The foregoing is merely illustrative of the principles of this disclosure, and various modifications can be made by those skilled in the art without departing from the scope of this disclosure. For example, in some embodiments, actuation delay can be improved by overlapping the end of speed matching with the start of drive. As another example, the verification phase can be modified to use an unloaded reference compared to the measured motor speed (e.g., integral motor torque feedback). Yet another example is that the verification phase can be replaced by a slow ramp-up of torque.

[0110] The aforementioned methods, control logic, and / or flowcharts can be implemented using a processing circuitry system (e.g., control system 110 or 302). In some embodiments, the vehicle may include processing circuitry. In some embodiments, the processing circuitry may include a processor and memory. The processor may include a hardware processor, a software processor (e.g., a processor simulated using a virtual machine), or any combination thereof. In some embodiments, the combination of processor and memory may be referred to as the vehicle's processing circuitry or control circuitry. In some embodiments, a single processor may be referred to as the vehicle's processing circuitry or control circuitry. The memory may include hardware elements for non-transitory storage of commands or instructions that, when executed by the processor or processing circuitry, cause the processor or processing circuitry to operate one or more disconnection devices in accordance with the present disclosure described above and below. The processing circuitry may be communicatively connected to one or more sensors (e.g., motor speed sensors and wheel speed sensors) and may be communicatively coupled to apply torque commands to one or more motors and actuation commands to one or more disconnection devices.

[0111] The above embodiments are presented for illustrative purposes and not for limitation. This disclosure may also take many forms other than those expressly described herein. Therefore, it should be emphasized that this disclosure is not limited to the methods, systems, and instruments expressly disclosed, but is intended to include variations and modifications thereof, which are within the scope of the following claims.

Claims

1. A method for engaging a disconnect device of a transmission system associated with a vehicle, comprising: The target motor speed is determined based on wheel speed and speed increment; The target motor speed is achieved by controlling the motor speed associated with the motor assembly via a control system associated with the vehicle. The control system facilitates the engagement of the transmission disconnect device to connect the motor assembly to the corresponding wheel; In response to the engagement of the transmission system disconnection device, the motor speed associated with the motor assembly is monitored via the control system; as well as The control system determines the successful engagement of the transmission system disconnection device based on the motor speed response.

2. The method of claim 1, wherein determining the engagement success based on the motor speed response includes determining the engagement success when the motor speed response indicates the presence of a load connected to the drive system disconnection device.

3. The method according to claim 2, further comprising determining the speed increment based on the vehicle speed.

4. The method of claim 3, wherein determining the speed increment based on the vehicle speed comprises: The vehicle speed is compared with a threshold. When the vehicle speed is lower than the threshold, a first speed increment is selected as the speed increment; and When the vehicle speed is higher than the threshold, a second speed increment is selected as the speed increment, wherein the second speed increment is greater than the first speed increment.

5. The method of claim 1, wherein determining the successful engagement of the transmission system disconnection device comprises: The motor speed response was determined not to indicate successful engagement; Apply torque pulses to the motor assembly; Determine the pulse motor speed response to the torque pulse; as well as The engagement is determined to be successful based on the speed response of the pulse motor.

6. The method of claim 5, wherein determining the engagement success based on the pulse motor speed response includes determining the engagement success when the pulse motor speed response indicates the presence of a load connected to the drive system disconnection device.

7. The method of claim 1, further comprising applying a diagnostic threshold to determine when the motor speed achieves the target motor speed corresponding to the speed increment.

8. The method of claim 7, wherein the diagnostic threshold represents the maximum permissible steady-state error.

9. The method of claim 7, wherein the diagnostic threshold is applied based on the magnitude of the error in the motor speed.

10. The method according to claim 1, further comprising: Receive the wheel speed.

11. The method of claim 10, wherein the target motor speed corresponds to a speed less than the wheel speed.

12. The method according to claim 1, further comprising: Determine whether the motor speed and the corresponding wheel speed are well correlated. Determining whether the engagement is successful also relies on determining whether the motor speed and the corresponding wheel speed are well correlated.

13. The method of claim 1, wherein facilitating the engagement of the transmission system disconnection device to connect the motor assembly to the corresponding wheel includes an actuating groove plate's support for engagement with a recess in the groove plate.

14. A system for engaging a transmission disconnect device associated with a vehicle, comprising: motor; Sensorless disconnect device; and Processing circuit, the processing circuit being configured to: The target motor speed is determined based on wheel speed and speed increment; Control the motor speed associated with the motor assembly to achieve the target motor speed; Facilitate the engagement of the sensorless disconnect device to connect the motor assembly to the corresponding wheel; In response to the engagement of the sensorless disconnect device, the motor speed associated with the motor assembly is monitored; and The engagement of the sensorless disconnect device is determined based on the motor speed response.

15. The system of claim 14, wherein the processing circuitry is further configured to determine the speed increment based on the vehicle speed.

16. The system of claim 15, wherein the processing circuitry is configured to determine the speed increment based on the vehicle speed in such a manner as follows: The vehicle speed is compared with a threshold. When the vehicle speed is lower than the threshold, a first speed increment is selected as the speed increment; and When the vehicle speed is higher than the threshold, a second speed increment is selected as the speed increment, wherein the second speed increment is greater than the first speed increment.

17. The system of claim 14, wherein the processing circuitry is configured to determine the engagement success by: The motor speed response was determined not to indicate successful engagement; Apply torque pulses to the motor; Determine the pulse motor speed response to the torque pulse; as well as The engagement is determined to be successful based on the speed response of the pulse motor.

18. The system of claim 14, wherein the processing circuit is further configured to: Receive the wheel speed.

19. The system of claim 14, wherein facilitating the engagement of the sensorless disconnection device to connect the motor assembly to the corresponding wheel includes an actuation plate post for engagement with a recess in the recessed plate.

20. A vehicle comprising: A first motor, the first motor being connected to a first wheel via a first disconnect device; A second motor is connected to a second wheel via a second disconnect device; and Processing circuit, the processing circuit being configured to: The target motor speed is determined based on wheel speed and speed increment; Control the speed of the first motor or the second motor to achieve the target motor speed; Facilitate the engagement of the first disconnection device or the second disconnection device to connect the first motor to the first wheel or the second motor to the second wheel; In response to the engagement of the first disconnecting device or the second disconnecting device, the motor speed of the first motor or the second motor is monitored; and The engagement of the first disconnecting device or the second disconnecting device is determined based on the motor speed response.

21. The vehicle of claim 20, wherein the first wheel comprises the left rear wheel of the vehicle, and the second wheel comprises the right rear wheel of the vehicle.

22. The vehicle of claim 20, wherein the processing circuitry is configured to engage the first disconnection device and the second disconnection device in response to the vehicle switching to four-wheel drive.

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